1. Field of the Invention
The invention relates to the field of food preparation. More particularly, the invention relates to a steam heating device and a method for its use that heats pre-processed food products to a desired temperature using controlled bursts of steam. The invention is particularly suited for use in a fast food restaurant, although it may find use in any restaurant or kitchen setting.
2. Description of the Related Art
The use of microwave ovens, food holding cabinets, and product holding units to heat and/or maintain at desired temperature levels pre-processed food products is well known in the fast-food restaurant art. The use of steam to heat and cook food products is also well known. In addition to the pressure cooker, which utilizes steam created under pressure to decrease cooking time, steam is used, for example, to heat food products in steam tables, and in steam enclosures. The prior-art heating devices and methods, however, suffer from a variety of drawbacks. It has been observed in consumer preference studies that food products heated by microwave may not be perceived as being fresh. Particularly with respect to baked goods such as sandwich buns and other pre-processed bread products, microwave heating may lead to an undesirable, soggy, or stale taste and texture. Additionally, food products heated in a microwave are not heated uniformly—resulting in hot and cold spots.
Other prior-art heating devices are deficient because they do not raise the temperature of the sandwich fast enough, do not have the necessary speed or ease of operation for the fast-food industry, or are cost prohibitive for a franchise-based business model. Of the commercially available heating devices examined, heated contact plates that provide conductive heat to the sandwich do not raise sandwich temperatures fast enough. Also the use of such plates on an assembly board in the fast paced environment of a fast-food kitchen are impractical. Convection based heating devices also do not raise the sandwich temperature fast enough and negatively affect sandwich quality. Infrared or lightwave heaters again do not raise the sandwich temperature to the desired level and are cost prohibitive. Conventional steam cabinets do not provide the needed product quality nor do they have the required speed or ease of operation.
The use of steam as a means of heating, while known, has heretofore not provided satisfactorily uniform results, particularly with respect to heating pre-processed food products such as baked goods, which may become soggy when exposed to a humid, steam environment. In prior-art steamers as well as in food holding cabinets using convective heating, it is difficult to control or maintain humidity at a desired level. Conventional steam cabinets also typically required time periods on the order of minutes to heat baked goods to temperatures in excess of 180° F. Moreover, since these steamers and ovens typically have relatively large sliding or hinged doors to load food products therein and remove the food products therefrom, heat and humidity escape from the unit. Additionally, these doors introduce inefficient employee movement and wasted labor by the constant opening and closing of the doors during the assembly process of a sandwich. And, such cabinets must be placed above or beside the sandwich assembly board—introducing even more inefficiency and wasted movement.
It is also well known in the fast-food art to prepare sandwiches utilizing a division of labor. Ordinarily one employee at an assembly station prepares part of a fast food sandwich and then hands the sandwich to a second employee who adds additional ingredients to the sandwich. This process is often repeated as necessary to assemble and wrap a complete sandwich ready for the consumer. This division of labor divides the product to be assembled between employees, (e.g. one employee assembles bun heels and meat patties while another prepares bun crowns and garnish) rather than dividing the equipment used in assembling the sandwich between employees.
The positioning of holding cabinets and microwaves around the assembly area has previously limited the assembly of fast food sandwiches to a method using a division of labor wherein the product to be assembled is divided between different employees positioned in front of the necessary holding cabinets, steam cabinets and/or microwaves and the various sandwich ingredients. Alternatively one employee would have to move down the length of the assembly board to assemble one sandwich. Whether utilizing a division of labor or a single employee walking the length of the board, the prior arrangement of holding cabinets, steam cabinets, and microwaves was plagued by inherent inefficiencies in assembling each sandwich, limited the available methods used to assemble sandwiches, and restricted menu options.
Sandwich assembly efficiency studies show that the most efficient method of assembling a sandwich divides the assembly process without dividing the product to be assembled. Prior art methods utilizing a division of labor that divides sandwich assembly between different employees yield a process that is 30–40% more efficient than one employee making the entire sandwich. Two employees making two sandwiches wherein each employee is positioned at his or her own individual workstation, nearly doubles the sandwich assembly efficiency and productivity.
Individual workstations, however, have not been incorporated in previous kitchen arrangements because of the related increase in cost and space. Sharing certain equipment, such as the steam heating device of the present invention, between employees without dividing the actual product to be assembled between multiple employees yields nearly 90% of the efficiency and productivity of individual workstations without the drawbacks of cost and space.
Consumer studies indicate that the average customer in a fast-food restaurant begins eating a fast-food sandwich approximately 2 to 3 minutes after purchase. But the average drive-through customer begins eating a fast-food sandwich approximately 7 minutes after purchasing a fast-food sandwich at the drive-through window. Consumer preference studies also show that customers prefer a fast-food sandwich when served at a temperature between the range of 150° F. to 160° F. Prior-art practices of cooking, heating, assembling, storing, and serving a sandwich have not been successful in maintaining a fresh tasting sandwich, within the desired serving temperature range of 150° F. to 160° F., for the range of time in which a consumer begins eating the sandwich, e.g. between approximately 2 to 7 minutes after purchase. In prior art practices, to maintain this temperature, the quality of condiments and garnish was sacrificed, as condiment temperatures often reached 115° F., rather than the customer preferred temperature range of approximately 90° F. to 100° F.